Multi-amine polyester dispersant made via an anhydride intermediate

ABSTRACT

The present invention relates to a dispersant derived from anhydride functionalized polyester derived from carboxylic acid functionalized polyester. The anhydride functionalized polyester is then reacted with a multi-amine species forming amide and salt bonds. The technology allows lower reaction temperatures when the multi-amine species is present. The lower reaction temperature allows the use of a broader selection of polyester repeat units.

This application claims priority from PCT Application Serial No.PCT/US2018/051449, filed on Sep. 18, 2018, which claims the benefit ofU.S. Provisional Application No. 62/560,317, filed on Sep. 19, 2017.

FIELD OF INVENTION

The present invention relates to a dispersant of a multi-amine species(a polyamine such as polyethyleneimine) reacted with multiple polyesterchains via an anhydride intermediate. The carboxylic acid chain ends ofthe polyester are converted to anhydride groups by dehydration prior tothe reaction with the multi-amine containing species.

BACKGROUND OF THE INVENTION

Polyamine derived dispersants are well known and are in general veryeffective pigments dispersants. The composition and molecular weight ofthe steric stabilization chains of these dispersants are criticallyimportant, both for the solubility of the dispersant and its physicalform. It is well known that dispersants based on polyester co-polymerscan offer fluidity and broader solubility in a variety of non-aqueousmedia of differing polarity.

EP208041 discloses a method where the mono acid functional polyester isheated with the polyamine, polyethyleneimine (PEI) in this case, at 120°C. for multiple hours to allow for the loss of water and the formationof some amide bonds, but not all of the polyester chains are attached tothe PEI and hence some remain as salt bond/linkages.

Dispersants based on polyethyleneimine that also contain polyesters arewell known. Examples include U.S. Pat. No. 6,197,877 where the“traditional” coupling approach of reacting a carboxylic acid endedpolyester with PEI above 100° C. to form some amide bonds, while leavingsome salt bonds.

US 2010/0174046 discloses a method for making the polyester chains insitu, by having the polyamine (PEI in this case) in the reaction at thestart using the amine groups as an initiator to ring open lactones, thisresults in a dispersant with polyester chains attached to the polyaminepredominately with amide bonds. This reaction is usually carried out attemperatures above 125° C. and again can involve the elimination ofwater where hydroxyl carboxylic acids are used as co-monomers.

U.S. Pat. No. 9,039,822 uses lactic acid (not lactide) and is the“traditional” approach of synthesizing the polyester first and couplingthereafter. These agents are used on ceramic inkjet pigments. Note thatthe polyester is carboxylic acid ended at one end and mainly —OH endedat the other. There is probably a small % of the polymers that are —Hended in example A and B as ricinoleic acid often contains low % ofoleic acid. However, the examples that contain lactone as the co monomerwith lactic acid are purely —OH ended.

However, these prior art processes have some inherent flaws, waterremoval from the reaction vessel has to be efficient, otherwise thereaction will be very slow, which in turn can lead to side reactionsoccurring. These side reactions include hydrolysis of the ester groupsin the polyester chain (cleaving the polyester into two smallerpolyester chains), or the primary or secondary amine groups of thepolyamine react with the ester functionalities of the polyester(cleaving the polyester into two smaller polyester chains and attachingone of the cleaved polyester segments to the polyamine via an amidebond).

Secondly, the prior art reaction has to be carried out at above 100° C.and preferably higher (such as above 140° C.) to allow for the bestremoval of water from the system (see above), however at this point thefree amine groups of the polyamine are present in the reaction mixtureand are therefore exposed to these high temperatures. Many polyamineswill readily darken when at elevated temperatures especially if thesereaction times are long and so can have negative consequences in someapplication areas such as white paint formulations.

It would be desirable if polyesters could be grafted onto polyamines ata lower temperature or under more mild conditions so that lessdegradation and yellowing of the polyamine would occur during synthesisof the graft copolymer.

Many formulations such as inks, paints, millbases and plastics materialsrequire effective dispersants for uniformly distributing a particulatesolid in a polar organic medium or a non-polar organic medium. Thepigment dispersion should be compatible with the different ink orcoating formulations.

SUMMARY OF THE INVENTION

One objective was to make new improved dispersants based on a polyaminespecies reacted with multiple polyester chains. There were concernsabout yellowing of the polyester polyamine dispersants made both by thetraditional approach (carboxylic acid ended polyester reacted withpolyamine) and by the grafting approach (polyamine initiatedpolymerization of lactones) where high temperature reaction conditionswere used, as described in US 2010/0174046 and US 2014/0012036.

Another objective is to prepare graft co-polymers comprising polyesterchains grafted onto polyamines under more controlled reaction conditionsthan in the prior art such that undesirable side reactions can beminimized, molecular weight and architecture of the polyester polyaminedispersant can be better controlled to result in more consistent productand less variability of the product due to molecular weight andmicrostructure variations.

It was found that when polyesters with terminal carboxylic acid groupswere converted to their polyester acid anhydride (by a dehydrationreaction with a low molecular weight monocarboxylic acid anhydride suchas acetic anhydride), the polyester anhydride intermediate could bereacted with the primary and/or secondary amine groups of a polyamine ata lower temperature (such as below 100° C.) to form amide and saltlinkages between the carboxylic functionality of the polyester and theamine functionality of the polyamine. This resulted in the formation ofpolyester polyamine dispersants which were less yellow in colourcompared to prior art. These lower temperatures also resulted in lessreaction between the amine atoms and the ester linkages of the polyesterchains, (resulting in less polyester chain scission), this is mostnotable when the polyester comprises of highly labile monomers such aslactide. This process also eliminated the presence of water in theformation of the dispersants to minimize or eliminate ester hydrolysis(chain scission of the polyester chain) and the formation of smallerpolyester chains.

We have developed the new method where the polyamine is only exposed tolower temperatures, such as <100° C., for much shorter reaction timesand wherein the formation of the potential water from making an amidebond from the reaction of the amine group with a carboxylic acid hasbeen removed, the reaction conditions to make the polyester polyaminedispersant is much less dependent on removing a large amount of waterand therefore the reaction conditions to achieve complete or almostcomplete reaction of the polyester with the polyamine is much lessdependent on reaction vessel size and shape.

The problem of chain scission is evident by the lack of operativeexamples that contain lactic acid, lactide, glycolic acid and glycolidemonomers, even when they are disclosed in the literature. These monomerscontain labile carbonyl groups and as such are more prone to chainscission in comparison to other monomers such as caprolactone and12-hydroxysteric acid.

In one embodiment, it was found that when lactide was incorporated intoa polyester and the polyester was then reacted with a polyamine species(such as PEI) at temperatures above 100° C. (such as 120° C.), there wasapparent chain scission at the ester groups of the polyester chain andthis resulted in dispersants that did not perform well as dispersants.While not wishing to be bound by theory, it is anticipated that underthe reaction conditions used, the amine groups were reacting at asignificant rate with the ester linkages of the polyester chain causingchain scission. It was also anticipated that dispersants with random lowmolecular weight polyester chains do not function as well as dispersantswith controlled molecular weight polyester chains (that can be optimizedfor efficiency in a particular solvent with a particular pigment).

In one embodiment, it has been found that when the above-mentionedlabile monomers such as lactide are incorporated into a polyester theycan be attached to a polyamine species (such as PEI) by first convertingthem into polyester anhydride and then reacting with the polyaminespecies for a short period of time a temperature lower than 100° C.Using this method, the chain scission is greatly reduced, leading topolyester chains of the required length attached to the polyaminespecies.

The dispersants resulting from these reactions showed good dispersingability with a variety of pigments and other particulates in a varietyof media. The dispersants were characterized by a low level of hydroxylterminal groups (as hydroxyl groups tended to get consumed in reactionwith the dehydrating agent) and chain scission to create new hydroxylgroups during reaction with the amine was reduced.

In one embodiment, the reactants used to form the polyester anhydride bydehydration of the carboxylic acid ended polyester can be removed fromthe polyester anhydride intermediate prior to the reaction with themulti-amine species.

In one embodiment, the reactants used to form the polyester anhydridemay still be present when addition to the polyamine species takes placeand hence modify it to a lesser or greater extent. If a volatileanhydride of two carboxylic acids is used to form the anhydride of thepolyester, and if a volatile carboxylic acid or anhydride of carboxylicacids is not removed prior to the reaction with the multi-amine species,they can react with the multi-amine species to form an amide or saltlinkage. This is not anticipated to be deleterious to the finaldispersant as the preferred carboxylic acids or anhydrides tend to bevolatile and low molecular weight and would not substantially change thehydrophilic/lipophilic character of the dispersant.

DETAILED DESCRIPTION OF THE INVENTION

For the sake of brevity, the summary of invention language descriptionwill not be repeated here. We will proceed to describe the structure ofthe dispersant, the changes to the dispersants that are consideredviable, the method of making the dispersant, pre or post reactionmodification of the dispersant, etc.

We have now discovered a way to reduce the yellowing of these polyestermulti amine dispersants, second embodiment to attach these interestinglactide (a cyclized dimer of two lactic acid units) or lactic acidcontaining polyester co-polymers to PEI without chain scissionoccurring, leading to dispersants with levels of performance asexpected.

The term hydrocarbyl will refer to monovalent hydrocarbon groups thatmay optionally include other heteroatoms (such as 0 and N) inconventional or specified amounts such as one oxygen and or nitrogen forevery two or every ten carbon atoms in the group, but preferably justcarbon and hydrogen. The term hydrocarbylene will refer to divalenthydrocarbon groups that may optionally include other heteroatoms such as0 and N as defined for hydrocarbyl.

A dispersant of the following structure:

wherein:

MA is a multi-amine species and desirably has a number average molecularweight (MW) between 300 and 100,000 g/mole, preferably between 600 and50,000 g/mole;

PE1 is a polyester chain of number average molecular weight (MW) between500 and 4,000 g/mole attached to the multi amine species (MA) via anamide bond;

the carbonyl group is from the terminal group of PE1 and the nitrogen isfrom the MA;

PE2 is a polyester chain of number average molecular weight (MW) between500 and 4,000 g/mole attached to the multi amine species (MA) via a saltlinkage;

the deprotonated carboxylic acid group is from the terminal group of PE2and the protonated nitrogen is from the MA; PE1 and PE2 can be mixturesof compositionally different polyester chains, but generally PE1 and PE2are similar polyester chains but are attached differently (one via anamide bond and the other via a salt of the amine with a carboxylic acidgroup);

A1 is the residue of a C₂₋₅ carboxylic acid (preferably C₂₋₃) attachedto the multi amine species (MA) via an amide bond, the carbonyl group isfrom the terminal group of A1 and the nitrogen is from the MA; and

A2 is the residue of a C₂₋₅ carboxylic acid (preferably C₂₋₃) attachedto the multi amine species (MA) via a salt linkage, the deprotonatedcarboxylic acid group is from the terminal group of A2 and theprotonated nitrogen is from the MA.

The relative molar ratios of amide bonds represented by p and p′ to saltlinkages represented by q and q′ are between 5:95 and 50:50;

p+p′ can never be greater than q+q′;

p is always 1 or greater than 1, and p′ is 1 or greater than 1;

q is always 1 or greater than 1, and q′ is 1 or greater than 1;

p+p′+q+q′ is between 4 and 2000; more desirably p+q being from 4 to 36;and

p′+q′ being at least 2 or at least 4.

And the weight ratio of the polyesters (combination of PE1 and PE2) tothe multi-amine species (MA) is desirably from 2:1-26:1; more desirablyfrom 2:1-25:1; and preferably from 3:1-20:1; and wherein Formula 1contains no more than 5 wt % of combined A1 and A2. The number averagemolecular weight of the dispersant is preferably not less than 2,000,more preferably not less than 2,500 and especially not less than 3,000.It is also preferred that the number average molecular weight of thedispersant is less than 1,000,000 more preferably less than 500,000 andmost preferably less than 250,000 g/mole.

This dispersant is desirably made via a three-step process. According tothe present invention, there is a method for forming a graft co-polymerof multiple polyester chains and a polyamine via an anhydrideintermediate of carboxylic acid terminated polyester chains. Thereaction to form the anhydride intermediate of the carboxylic acid endedpolyester occurs at elevated temperature and can be facilitated byadding anhydrides of low molecular weight C2-5 carboxylic acids selectedfrom the group consisting of acetic acid, propionic acid, and butyricacid.

Step 1 is the synthesis of a mono functional acid polyester which can bedescribed as:R₁—[OR₃—C(═O)]_(n)—OHwherein:

R₁ is H— or R₂C(═O)—;

R₂ is a branched or linear, saturated or unsaturated hydrocarbon chaincontaining between 1 and 25 carbons atoms;

R₃ is a branched or linear, saturated or unsaturated hydrocarbon chaincontaining between 1 and 25 carbons atoms or —R₄—OC(═O)R₅—; andoptionally up to 50 mole %, more desirably up to 30 mole % andpreferably up to 20 mole % of the R₃ units (based on the total units ofR₃) in a mono functional acid polyester contains a hydroxy pendant groupor an oxygen atom (derived from the hydroxyl group) of an ester linkagewith a polyester chain of the structure R₁—[OR₃—C(═O)]_(n)—; (this isshown in dispersant 20 in the examples and thus the polyester ispredominantly the units shown with the option of a few percent (up to20, 30, or 50 mole %) being branched ester units of a particular estertype where the branching is derived from a hydroxy branched orsubstituted version of (O—R₃));

R₄ is a branched or linear, saturated or unsaturated hydrocarbon chaincontaining between 2 and 30 carbons atoms, which may optionally contain1 or more ether linkages;

R₅ is a branched or linear, saturated or unsaturated hydrocarbon chaincontaining between 1 and 20 carbons atoms; and

n is between 3 and 43.

Hence, R₁—[OR₃—C(═O)]_(n)—OH describes a mono acid functional homo orco-polyester with a MW of between 500 and 4000.

This mono acid functional polyester can be synthesized by any methodknown to those skilled in the art but especially via either a)polymerization of lactones and/or lactides and/or hydroxycarboxylicacids optionally in the presence of monocarboxylic acids to initiate thepolyester chain extension or b) polymerization reaction of a diol with adibasic acid or derivatives thereof such as acid chlorides, anhydride ordialkylesters in the presence of a stoichiometric amount ofmonocarboxylic acid to control molecular weight and suppress formationof dihydroxy polyesters.

Examples of suitable hydroxyl carboxylic acids and lactones and lactidesused to prepare the polyester chains include hydroxy-substituted C2-30alkylene carboxylic acid, a hydroxy-substituted C4-30 alkenylenecarboxylic acid, lactones or mixtures thereof. Specific examples ofsuitable hydroxy carboxylic acids are ricinoleic acid, 12-hydroxystearicacid, 6-hydroxy caproic acid, 5-hydroxy valeric acid, 12-hydroxydodecanoic acid, 5-hydroxy dodecanoic acid, 5-hydroxy decanoic acid,4-hydroxy decanoic acid, 10-hydroxy undecanoic acid, lactide, glycolide,glycolic acid and lactic acid. Examples of the lactones is preferablyoptionally C1-4 alkyl substituted ε-caprolactone, optionally substitutedC1-4 alkyl δ-valerolactone and β-propiolactone. The hydroxy carboxylicacids and lactones can also include di-hydroxy compounds of the samecarbon range and substitution such as 2,2-bis(hydroxymethyl)butyricacid; 2,2-bis(hydroxymethyl)propionic acid, and similar dihydroxycarboxylic acids in the specified carbon range. These would formbranched polyester that would still have one carboxylic acid terminalgroup per polyester wherein the carboxylic acid group could be convertedto an anhydride as taught in this disclosure.

Use of the above described components to make the polyester portion ofthe dispersant will result in various R₃ groups. In one embodiment, theR₃ is a branched or linear, saturated or unsaturated hydrocarbon chaincontaining between 1 and 25 carbons atoms or —R₄—OC(═O)R₅—, wherein R₄is a branched or linear, saturated or unsaturated hydrocarbon chaincontaining between 2 and 30 carbons atoms, which may optionally contain1 or more ether linkages, R₅ is a branched or linear, saturated orunsaturated hydrocarbon chain containing between 1 and 20 carbons atoms,and n is between 3 and 43.

In another embodiment, at least 10 mole % (more desirably at least 20,and preferably at least 30 mole %) of the R₃ units are linear orbranched alkyl groups of 1 to 5 carbon atoms (these R₃ assignments arerepresentative of combinations of glycolic, lactic, caprolactone, andvalerolactone). In another embodiment, at least 10 mole % (moredesirably at least 20, and preferably at least 30 mole %) of the R₃units are linear or branched alkyl groups of 4 and/or 5 carbon atoms(this is representative of cap or cap val). In another embodiment, atleast 10 mole % (more desirably at least 20, and preferably at least 30mole %) of the R₃ units are linear or branched alkyl groups of 6 to 17carbon atoms (this is representative of oleophilic hydroxycarboxylicacid). In yet another embodiment, at least 5 mole % (more desirably atleast 10 or 20, and preferably at least 30 mole %) of the R₃ units arelinear or branched alkyl groups of 1 or 2 carbon atoms (this isrepresentative of repeat units from lactide or glycolic). In anotherembodiment, combinations of the at least amounts from the prior foursentences can be combined to get preferred polyester portions of thedispersant.

Specific examples of suitable diols include alkylene glycols such asethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol,1,6-hexanediol, cis and trans 1,2- and 1,4-cyclohexanedimethanol, diolswith ether linkages such as diethylene glycol, dipropylene glycol,tripropylene glycol and triethylene glycol, polyalkylene glycols such aspolyethylene glycols, polypropylene glycols, polybutylene glycols, mixedblock and random copolymers of polyethylene glycol and polypropyleneglycol (Pluronic™ and reverse Pluronic™ ex BASF) with MW less than 1000.

Specific examples of the dibasic acids, diesters and anhydrides includemaleic anhydride, succinic anhydride, glutaric acid, fumaric acid,malonic acid, adipic acid, sebacic acid, phthalic anhydride, pimelicacid, dimer fatty acids and their hydrogenated versions, and cyclohexanedicarboxylic anhydride.

Examples of monocarboxylic acids used to initiate a) the polymerizationof the lactones and/or the hydroxycarboxylic acids or b) thecondensation of diols with dicarboxylic acids or their esterifiablederivatives such as anhydride, diesters and acid chlorides include C1-25carboxylic acids which may be saturated, unsaturated, branched, alkyl oraryl and may be substituted with C1-4 alkoxy or halogen. Specificexamples include propionic acid, oleic, palmitic, stearic, erucic,lauric, 2-ethylhexanoic, 9,11- and 9,12-linoleic, 9,12,15-linolenicacids, abietic acid, methoxyacetic, 2,2-dimethyl butanoic acid andcaproic acid.

The mono carboxylic acid ended polyester in one embodiment is preparedfrom a lactone and/or lactide and/or a hydroxycarboxylic acid at atemperature from 50 to 250° C., optionally in the presence of a monocarboxylic acid and optionally in the presence of an esterificationcatalyst. In one embodiment, the temperature is not less than 100° C. ornot less than 150° C. In order to minimise any charring of the finalproduct, the temperature is generally not greater than 200° C. In oneembodiment, up to 20, 30 or 50 mole % of the combined lactone, lactide,and hydroxycarboxylic acid reactants are dihydroxycarboxylic acids.

The inert atmosphere may be provided by any inert gas of the PeriodicTable but is generally nitrogen. In one embodiment, the reaction iscarried out in the presence of an esterification catalyst such as ametal alkoxide such as zirconium butoxide, tetraisopropyltitanate ortetrabutyl titanate, a zinc salt of an organic acid, for example zincacetate, a tin catalyst such as stannous chloride, stannous octylate,dibutyl tin dilaurate or monobutyl tin oxide or an acid catalyst such astoluene sulphonic acid or trifluoroacetic acid.

For reaction conditions and process steps for formation of the polyesterchains using diols and diacids. Please see U.S. Pat. No. 5,760,257,column 5.

Step 2 is the conversion of the above-mentioned mono carboxylic acidfunctional polyester to an anhydride via reaction with a low boilinganhydride in the following fashion:either2×R₁—[OR₃—C(═O)]_(n)—OH+R₆C(═O)OC(═O)R₆→R₇—[OR₃—C(═O)]_(n)—O—[C(═O)—R₃O]_(n)R₇+2×R₆C(═O)OH;and/orR₁—[OR₃—C(═O)]_(n)—OH+R₆C(═O)OC(═O)R₆→R₇—[OR₃—C(═O)]_(n)—O—C(═O)R₆+R₆C(═O)OH.

where R₁, R₂, R₃, and n are described above.

R₆ is a branched or linear hydrocarbon chain containing between 1 and 4carbon atoms, preferably between 1 and 2 carbon.

R₇ is R₂C(═O)— or R₆C(═O)—.

It should be noted that any mono acid functional polyester where R₁ isH, the end hydroxyl group will be converted to an ester group and bedescribed as R₆C(═O)—, and hence why the terminal R₁ group of thepolyester changes to R₇.

This process is carried out by mixing the mono functional acid polyesterin the presences of molar excess of the low boiling anhydride at anelevated temperature. This temperature can be up to 15° C. lower thanthe boiling point of the low boiling anhydride if the reaction vesselhas a set up where volatile material can be removed for example the useof a trap or open port, or at temperature up to the boiling point of thelow boiling anhydride if the setup is such that any volatile material isreturned for example the use of a condenser. Preferred low temperatureboiling anhydrides are conveniently selected from the group consistingof acetic anhydride, propionic anhydride, and butyric anhydride.

After one to 24 hours of mixing, the remaining excess low boilinganhydride and any of its associated acid (that has not already beenremoved from the reaction vessel) can be removed by ensuring thereaction set up will allow volatile material to escape, for example,through the use of a trap or open port, and the temperature raised to begreater than the boiling point of the low boiling anhydride.

U.S. Pat. No. 2,411,567 teaches about synthesizing joint anhydrides ofthe acids using acetic anhydride but for non-polymeric acids.

Step 3 is the above synthesized anhydride of the mono functional acidpolyester is then reacted with a polyamine to result in a mixture ofamide and salt bonds between the polyesters and the polyamine, as shownby the below structure.EitherR₇—[OR₃—C(═O)]_(n)—O—[C(═O)—R₃O]_(n)R₇+(H—)_(m)N-MA′-N(—H)_(m)→R₇—[OR₃—C(═O)]_(n)—N(—H)_(m−1)-MA′-N⁺(—H)_(m+1)⁻O—[C(═O)—R₃O]_(n)R₇, where m is 1 or 2; and/or2×R₇—[OR₃—C(═O)]_(n)—O—C(═O)R₆+2×(H—)_(m)N-MA′-N(—H)_(m)→R₇—[OR₃—C(═O)]_(n)—N(—H)_(m−1)-MA′-N⁺(—H)_(m+1)⁻O—C(═O)R₆+R₇—[OR₃—C(═O)]_(n)—O⁻⁺N(—H)_(m+1)-MA′-N(—H)_(m−1)—C(═O)R₆.

where R₃, R₆, R₇ and n are defined above and (H—)_(m)N-MA′-N(—H)_(m) isused to represent MA the multi amine species with only 2 N(—H)_(m)groups illustrated but containing between 6 and 1500 N(—H)_(m) groupswhich may optionally react with additional anhydride and/or carboxylicacid species and m is 1 or 2 depending whether the nitrogen atom, N, isa primary or secondary amine group.

This reaction of the terminal anhydride group with an amine to form anamide linkage or carboxylic acid-amine salt can be carried out atreaction temperature lower than 100° C. and for short reaction timessuch as 10 minutes, as the amines of the polyamine will readily reactwith the anhydride, this can be confirmed by IR and the disappearance ofthe anhydride peak at approximately 1820 cm⁻¹. The limiting factor onthe temperature and time of this reaction is the physical form of the 2polymers (polyester and polyamine) and subsequently the ability to mixthem efficiently and thoroughly to get a uniform reaction product,optionally the reaction may be carried out in a suitable solvent. Theselower temperatures resulted in less reaction between the amine atoms andthe ester linkages (resulting in less polyester chain scission).

MA is a polyamine and desirably has a number average molecular weightbetween 300 and 100,000 g mole and is selected from polyethyleneimine,modified polyethyleneimine, polyallylamine, modified polyallylamine,polyvinylamine, modified polyvinylamine or mixtures thereof. In oneembodiment, it is preferred that at least 70, 80, 90 or 95 weightpercent of the multi-amine species is polyethyleneimine. It is desirablethat the multi-amine species has a number average molecular weight byebullioscopic method analysis of from 500 to 600,000 g/mole, moredesirably from about 1000 to 200,000 g/mole and preferably from about1000 to 100,000 or from 8000 to 100,000 g/mole.

The polyamine MA in one embodiment is poly(C₂₋₆-alkyleneimine) and/orpolyethylene imine. The polyamine may be linear or branched. Linearpolyethyleneimines may be prepared by hydrolysis of poly (N-acyl)alkyleneimines as described, for example, by Takeo Saegusa et al inMacromolecules, 1972, Vol. 5, page 4470. The branched polyethyleneiminesof differing molecular weights are commercially available from BASF andNihon Shokubai. Polyallylamine and poly-(N-alkyl) allylamines ofdiffering molecular weights are commercially available from NittoBoseki. Polyvinylamine of differing molecular weights are available fromMitsubishi Kasai. Poly(propyleneimine) dendrimers are commerciallyavailable from DSM Fine Chemicals and poly(amidoamine) dendrimers areavailable as “Starburst” dendrimers from Aldrich Chemical Co.

In one embodiment, the polyamine MA can be modified by reacting aportion of its primary and/or secondary amino groups with esters such asethyl or butyl acetate, isocyanates such as phenyl isocyanate, lactonessuch as caprolactone and valerolactone, anhydrides such as succinic ormaleic or phthalic anhydride, cyclic carbonates such as ethylenecarbonate, or (meth)acrylates such as ethyl acrylate or 2-hydroxyethylacrylate, while ensuring there are still primary and/or secondary aminogroups of the modified polyamine that are unmodified and hence still inthe amine form.

In one embodiment, the polyamine MA can be polyethylene imine and thiscan be modified by substituting one or more protons of the NH units by aC2-4 alkyleneoxy unit. Polyethyleneimine can be modified by alkoxylationusing a C2-4 alkylene oxide such as ethylene oxide, propylene oxide,butylene oxide or mixtures thereof. Examples of alkoxylatedpolyethyleneimines are commercially available from BASF and NihonShokubai.

In one embodiment, the dispersant of Formula 1 can be furtherfunctionalized to adapt its properties and application performance tospecific requirements. These modification reactions below are betweenthe various reagents listed below and the amines of the polyaminespecies that have not already been reacted with the polyester anhydridein Step 3 detailed above. The modification of any remaining amino groupsmay take place in a way which is known to the skilled person. Suchmodifications are preferred when, for example, amino groups will reactwith a binder system into which the pigment paste is incorporated andcause flocculation.

The stated modifications are advantageous embodiments of the presentinvention and can be realized by:

a) reaction of one or more of the remaining free primary and secondaryamino groups of the polyamine species with isocyanates, lactones,anhydrides, epoxides, cyclic carbonates, or (meth)acrylates. Specificexamples of suitable isocyanates include phenyl isocyanate. Specificexamples of suitable lactones include caprolactone and valerolactone.Reaction of one or more of the remaining free primary and secondaryamino groups of the polyamine species with anhydrides are disclosed inU.S. Pat. Nos. 6,878,799 and 7,767,750. Specific examples of suitableanhydrides include maleic anhydride, succinic anhydride, phthalicanhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalicanhydride, hexahydrophthalic anhydride, methylhexahydrophthalicanhydride, 1,8-naphthalic anhydride, optionally substituted with nitroor halogen substituents such as Cl and Br, isatoic anhydride,trimellitic anhydride, C₁₋₂₀ alkenyl and alkyl succinic anhydrides.Reaction of one or more of the remaining free primary and secondaryamino groups of the polyamine species with epoxides is disclosed inJP4031471. Specific examples of suitable epoxides include styrene oxide,propylene oxide and ethylene oxide. Specific examples of suitable cycliccarbonates include ethylene carbonate and 2,2-dimethyltrimethylenecarbonate. Specific examples of suitable (meth)acrylates includes ethylacrylate and 2-hydroxyethyl acrylate;

b) salification and/or reaction of one or more of the remaining freeprimary, secondary or tertiary amino groups of the polyamine specieswith mono or polycarboxylic acids, mineral acids, phosphorus andpolyoxometallate containing acids or strong acids. Suitable reagents forthis purpose include hydrochloric acid, acetic acid, sulphuric acid,alkyl sulphonic acids, alkyl hydrogen sulphates or aryl sulphonic acids.Salification and/or reaction of one or more of the remaining free aminogroups of the aminic polyamine species with mono or polycarboxylic acidsor phosphorus containing acids are disclosed in JP9157374, US2010/0017973 and US 2013/0126804. Specific examples of suitable monocarboxylic acids include optionally substituted C1-50 aliphaticmonocarboxylic acids such as acetic acid, propionic acid, caproic acid,caprylic acid, 2-ethylhexanoic acid, nonanoic acid, decanoic acid,lauric acid, myristic acid, palmitic acid, oleic acid, linoleic acid,stearic acid, arachidic acid, erucic acid, behenic acid, methoxyaceticacid, mixtures of fatty acids derived from oils from naturally occurringsources such as sunflower oil, rape seed oil, castor oil and olive oil,branched alkyl carboxylic acids available under the trademark Isocarb™(ex Sasol), Unicid™ acids which are linear C25-50 synthetic primaryacids commercially available from Baker Hughes and aromatic carboxylicacids such as benzoic acid, salicylic acid and naphthoic acid. Specificexamples of suitable polycarboxylic acids include succinic acid, malonicacid, adipic acid, sebacic acid, malic acid, fumaric acid, citric acidand tartaric acid. Specific examples of suitable phosphorus containingacids include phosphoric acid and phosphorous acid. Specific examples ofsuitable polyoxometallate containing acids include phosphomolybdic acid,phosphotungstic acid and silicomolybdic acid;

c) oxidation of one or more of the remaining free primary, secondary ortertiary amino groups of the polyamine species to nitrogen oxides;

d) quaternization of one or more of the remaining free tertiary aminogroups of the polyamine species. This can be achieved using, alkylsulfates, alkyl or aralkyl halides, halocarboxylic esters, alkyloxalates or epoxides. Suitable reagents for this purpose include,dimethyl sulphate, benzyl chloride, methyl halides such as chlorine,bromine and iodine, dimethyl oxalate, ethylene oxide, propylene oxideand styrene oxide in the presence of acids, and propane (or butane)sultone; and

e) reaction of one or more of the remaining free primary, secondary ortertiary amino groups of the polyamine species with one or more monoamino-reactive group terminated polymer(s) of MW 150-3000. Suitableexamples of carboxylic acid terminated polyester, polyesteramide andpolyamide polymers are disclosed in U.S. Pat. Nos. 4,224,212, 4,861,380,5,700,395, 5,760,257, 6,197,877, 8,202,935, JP4866255, JP8010601,JP9157361, WO 2006/113258 and WO 2007/039605. Suitable examples ofcarboxylic acid terminated polyether polymers are disclosed inJP4248207, U.S. Pat. Nos. 7,767,750, 7,671,119, 7,872,070, 8,076,409 and8,168,713. Suitable examples of phosphate, sulphate and sulphonateterminated polyester polymers are disclosed in U.S. Pat. Nos. 4,861,380and 6,197,877. Suitable examples of (meth)acrylate terminated polyester,polyesteramide and polyamide polymers are disclosed in EP713894,JP3488001, JP2010-222522 and U.S. Pat. No. 8,202,935. Suitable examplesof (meth)acrylate terminated polyether polymers are disclosed in U.S.Pat. No. 7,923,474 and JP2010-222522. Suitable examples of phosphate,sulphate and sulphonate terminated polyether, polyether/polyester,polyether/polyurethane and polyether/polyester/polyurethane polymers aredisclosed in U.S. Pat. Nos. 5,130,463, 5,151,218, 6,111,054, 6,310,123,7,595,416 and 8,202,935. Suitable examples of isocyanate terminatedpolyester and polyether polymers are disclosed in JP4031471, JP7149855and WO 2007/039605. Suitable examples of epoxide or acetoacetoxy orcyclocarbonate terminated polyacrylate polymers are disclosed in U.S.Pat. No. 5,100,969.

One objective of the present invention is to provide compounds that arecapable of improving the colour strength or other tinctorial properties,increasing a particulate solid load, and/or forming improveddispersions, having improved brightness of the final composition. Thisis achieved while also producing a composition with reduced viscosity,good dispersion stability, reduced particle size and reduced particlesize distribution, reduced haze, improved gloss, and increased jetness(especially when the composition is black). The composition(s) of thepresent invention may also be stable under ambient storage, and hightemperature storage conditions providing reduceddiscolouration/yellowing of final coatings.

The polymer of the invention herein is useful as a dispersant forvarious small particle dispersions such as suspendable pigments andparticulates in various polar and non-polar media. The compositions ofvarious particulates, the dispersant, and a continuous phase are usefulas inks, coatings, paints, and millbases for coloring inks, coatings,and paints.

Thus, when the dispersant is to be used to disperse a particulate solidin a non-polar medium, preferably one or more of the hydroxy carboxylicacids containing a C₇₋₁₇-alk(en)ylene group are used. When a dispersantis desired to be used to disperse a particulate solid in a polar medium,it is preferred that one or more and especially all of the hydroxycarboxylic acids or lactones thereof contains a C₁₋₆-alkylene group.

INDUSTRIAL APPLICATION

The particulate solid present in the composition may be any inorganic ororganic solid material which is substantially insoluble in the organicmedium at the temperature concerned and which it is desired to stabilizein a finely divided form therein. The particulate solids may be in theform of a granular material, a fibre, a platelet or in the form of apowder, often a blown powder. In one embodiment, the particulate solidis a pigment.

The particulate solid (typically a pigment or filler) may have anaverage particle size measured by light scattering measurements of from10 nanometers to 10 microns, or 10 nanometers to 1, 2, 3 or 5 microns,or 20 nanometers to 1, 2, 3 or 5 microns in diameter.

Examples of suitable solids are pigments for solvent inks; pigments,extenders, fillers, blowing agents and flame retardants for paints andplastic materials; dyes, especially disperse dyes; optical brighteningagents and textile auxiliaries for solvent dyebaths; pigments for inks,toners and other solvent application systems; solids for oil-based andinverse-emulsion drilling muds; dirt and solid particles in dry cleaningfluids; metals; particulate ceramic materials and magnetic materials forceramics, piezo ceramic printing, refractories, abrasives, foundry,capacitors, fuel cells, Ferro fluids, conductive inks, magneticrecording media, water treatment and hydrocarbon soil remediation;organic and inorganic monodisperse solids; metal, metal oxides andcarbon for electrodes in batteries, fibers such as wood, paper, glass,steel, carbon and boron for composite materials; and biocides,agrochemicals and pharmaceuticals which are applied as dispersions inorganic media.

In one embodiment, the solid is an organic pigment from any of therecognised classes of pigments described, for example, in the ThirdEdition of the Colour Index (1971) and subsequent revisions of, andsupplements thereto, under the chapter headed “Pigments.” Examples oforganic pigments are those from the azo, disazo, trisazo, condensed azo,azo lakes, naphthol pigments, anthanthrone, anthrapyrimidine,anthraquinone, benzimidazolone, carbazole, diketopyrrolopyrrole,flavanthrone, indigoid pigments, indanthrone, isodibenzanthrone,isoindanthrone, isoindolinone, isoindoline, isoviolanthrone, metalcomplex pigments, oxazine, perylene, perinone, pyranthrone,pyrazoloquinazolone, quinacridone, quinophthalone, thioindigo,triarylcarbonium pigments, triphendioxazine, xanthene and phthalocyanineseries, especially copper phthalocyanine and its nuclear halogenatedderivatives, and also lakes of acid, basic and mordant dyes. Carbonblack, although strictly inorganic, behaves more like an organic pigmentin its dispersing properties. In one embodiment, the organic pigmentsare phthalocyanines, especially copper phthalocyanines, monoazos,disazos, indanthrones, anthranthrones, quinacridones,diketopyrrolopyrroles, perylenes and carbon blacks.

Examples of inorganic pigments include metallic oxides such as titaniumdioxide, rutile titanium dioxide and surface coated titanium dioxide,titanium oxides of different colors such as yellow and black, ironoxides of different colors such as yellow, red, brown and black, zincoxide, zirconium oxides, aluminium oxide, oxymetallic compounds such asbismuth vanadate, cobalt aluminate, cobalt stannate, cobalt zincate,zinc chromate and mixed metal oxides of two or more of manganese,nickel, titanium, chromium, antimony, magnesium, praseodymium, cobalt,iron or aluminium, Prussian blue, vermillion, ultramarine, zincphosphate, zinc sulphide, molybdates and chromates of calcium and zinc,metal effect pigments such as aluminium flake, copper, and copper/zincalloy, pearlescent flake such as lead carbonate and bismuth oxychloride.

Inorganic solids include extenders and fillers such as ground andprecipitated calcium carbonate, calcium sulphate, calcium oxide, calciumoxalate, calcium phosphate, calcium phosphonate, barium sulphate, bariumcarbonate, magnesium oxide, magnesium hydroxide, natural magnesiumhydroxide or brucite, precipitated magnesium hydroxide, magnesiumcarbonate, dolomite, aluminium trihydroxide, aluminium hydroperoxide orboehmite, calcium and magnesium silicates, aluminosilicates includingnanoclays, kaolin, montmorillonites including bentonites, hectorites andsaponites, ball clays including natural, synthetic and expandable, mica,talc including muscovites, phlogopites, lepidolites and chlorites,chalk, synthetic and precipitated silica, fumed silica, metal fibres andpowders, zinc, aluminium, glass fibres, refractory fibres, carbon blackincluding single- and multi-walled carbon nanotubes, reinforcing andnon-reinforcing carbon black, graphite, Buckminsterfullerene,asphaltene, graphene, diamond, alumina, quartz, perlite, pegmatite,silica gel, wood flour, wood flake including soft and hard woods, sawdust, powdered paper/fibre, cellulosic fibres such as kenaf, hemp,sisal, flax, cotton, cotton linters, jute, ramie, rice husk or hulls,raffia, typha reed, coconut fibre, coir, oil palm fibre, kapok, bananaleaf, caro, curaua, henequen leaf, harakeke leaf, abaca, sugar canebagasse, straw, bamboo strips, wheat flour, MDF and the like,vermiculite, zeolites, hydrotalcites, fly ash from power plants,incinerated sewage sludge ash, pozzolanes, blast furnace slag, asbestos,chrysotile, anthophylite, crocidolite, wollastonite, attapulgite and thelike, particulate ceramic materials such as alumina, zirconia, titania,ceria, silicon nitride, aluminium nitride, boron nitride, siliconcarbide, boron carbide, mixed silicon-aluminium nitrides and metaltitanates; particulate magnetic materials such as the magnetic oxides oftransition metals, often iron and chromium, e.g., gamma-Fe₂O₃, Fe₃O₄,and cobalt-doped iron oxides, ferrites, e.g. barium ferrites; and metalparticles, for instance metallic aluminium, iron, nickel, cobalt,copper, silver, gold, palladium, and platinum and alloys thereof.

Other useful solid materials include flame retardants such aspentabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenylether, hexabromocyclododecane, ammonium polyphosphate, melamine,melamine cyanurate, antimony oxide and borates; biocides or industrialmicrobial agents such as those mentioned in tables 2, 3, 4, 5, 6, 7, 8and 9 of the chapter entitled “Industrial Microbial Agents” inKirk-Othmer's Encyclopedia of Chemical Technology, Vol. 13, 1981, 3^(rd)Edition, and agrochemicals such as the fungicides flutriafen,carbendazim, chlorothalonil and mancozeb.

The organic medium present in the composition of the invention in oneembodiment is a plastics material and in another embodiment an organicliquid. The organic liquid may be a non-polar or a polar organic liquid.By the term “polar,” in relation to the organic liquid, it is meant thatan organic liquid is capable of forming moderate to strong bonds asdescribed in the article entitled “A Three Dimensional Approach toSolubility” by Crowley et al in Journal of Paint Technology, Vol. 38,1966, page 269. Such organic liquids generally have a hydrogen bondingnumber of 5 or more as defined in the above-mentioned article.

Examples of suitable polar organic liquids are amines, ethers,especially lower alkyl ethers, organic acids, esters, ketones, glycols,glycol ethers, glycol esters, alcohols and amides. Numerous specificexamples of such moderately strongly hydrogen bonding liquids are givenin the book entitled “Compatibility and Solubility” by Ibert Mellan(published in 1968 by Noyes Development Corporation) in Table 2.14 onpages 39-40 and these liquids all fall within the scope of the termpolar organic liquid as used herein.

In one embodiment, polar organic liquids are dialkyl ketones, alkylesters of alkane carboxylic acids and alkanols, especially such liquidscontaining up to, and including, a total of 6 carbon atoms. As examplesof the polar organic liquids include dialkyl and cycloalkyl ketones,such as acetone, methyl ethyl ketone, diethyl ketone, di-isopropylketone, methyl isobutyl ketone, di-isobutyl ketone, methyl isoamylketone, methyl n-amyl ketone and cyclohexanone; alkyl esters such asmethyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, ethylformate, methyl propionate, methoxypropyl acetate and ethyl butyrate;glycols and glycol esters and ethers, such as ethylene glycol,2-ethoxyethanol, 3-methoxypropylpropanol, 3-ethoxypropylpropanol,2-butoxyethyl acetate, 3-methoxypropyl acetate, 3-ethoxypropyl acetateand 2-ethoxyethyl acetate; alkanols such as methanol, ethanol,n-propanol, isopropanol, n-butanol and isobutanol (also known as2-methylpropanol), terpineol and dialkyl and cyclic ethers such asdiethyl ether and tetrahydrofuran. In one embodiment, solvents arealkanols, alkane carboxylic acids and esters of alkane carboxylic acids.In one embodiment, the present invention is suitable for organic liquidsthat are substantially non-soluble in an aqueous medium. Furthermore, aperson skilled in the art will appreciate that small quantities of anaqueous medium (such as glycols, glycol ethers, glycol esters andalcohols) may be present in the organic liquids provided the overallorganic liquid is substantially non-soluble in an aqueous medium.

Examples of organic liquids, which may be used as polar organic liquidsare film-forming resins such as are suitable for the preparation ofinks, paints and chips for use in various applications such as paintsand inks. Examples of such resins include polyamides, such as Versamid™and Wolfamid™, and cellulose ethers, such as ethyl cellulose and ethylhydroxyethyl cellulose, nitrocellulose and cellulose acetate butyrateresins, including mixtures thereof. Examples of paint resins includeshort oil alkyd/melamine-formaldehyde, polyester/melamine-formaldehyde,thermosetting acrylic/melamine-formaldehyde, long oil alkyd, medium oilalkyd, short oil alkyd, polyether polyols and multi-media resins such asacrylic and urea/aldehyde.

The organic liquid may be a polyol, that is to say, an organic liquidwith two or more hydroxyl groups. In one embodiment, polyols includealpha-omega diols or alpha-omega diol ethoxylates.

In one embodiment, non-polar organic liquids are compounds containingaliphatic groups, aromatic groups or mixtures thereof. The non-polarorganic liquids include non-halogenated aromatic hydrocarbons (e.g.toluene and xylene), halogenated aromatic hydrocarbons (e.g.chlorobenzene, dichlorobenzene, chlorotoluene), non-halogenatedaliphatic hydrocarbons (e.g. linear and branched aliphatic hydrocarbonscontaining six or more carbon atoms both fully and partially saturated),halogenated aliphatic hydrocarbons (e.g. dichloromethane, carbontetrachloride, chloroform, trichloroethane) and natural non-polarorganics (e.g. vegetable oil, sunflower oil, rapeseed oil, linseed oil,terpenes and glycerides).

In one embodiment, the organic liquid comprises at least 0.1% by weight,or 1% by weight or more of a polar organic liquid based on the totalorganic liquid. In one embodiment, the organic liquid is free of water.

The plastics material may be a thermosetting resin. The thermosettingresins useful in this invention include resins which undergo a chemicalreaction when heated, catalyzed, or subject to ultra-violet, laserlight, infra-red, cationic, electron beam, or microwave radiation andbecome relatively infusible. Typical reactions in thermosetting resinsinclude oxidation of unsaturated double bonds, reactions involvingepoxy/amine, epoxy/carbonyl, epoxy/hydroxyl, reaction of epoxy with aLewis acid or Lewis base, polyisocyanate/hydroxy, amino resin/hydroxymoieties, free radical reactions or polyacrylate, cationicpolymerization of epoxy resins and vinyl ether and condensation ofsilanol. Examples of unsaturated resins include polyester resins made bythe reaction of one or more diacids or anhydrides with one or morediols. Such resins are commonly supplied as a mixture with a reactivemonomer such as styrene or vinyltoluene and are often referred to asorthophthalic resins and isophthalic resins. Further examples includeresins using dicyclopentadiene (DCPD) as a co-reactant in the polyesterchain. Further examples also include the reaction products of bisphenolA diglycidyl ether with unsaturated carboxylic acids such as methacrylicacid, subsequently supplied as a solution in styrene, commonly referredto as vinyl ester resins.

In one embodiment, the thermosetting composite or thermosetting plasticmay be a polyester, a polyvinyl acetate, a polyester resin in styrene, apolystyrene, or mixtures thereof.

Polymers with hydroxy functionality (frequently polyols) are widely usedin thermosetting systems to crosslink with amino resins orpolyisocyanates. The polyols include acrylic polyols, alkyd polyols,polyester polyols, polyether polyols and polyurethane polyols. Typicalamino resins include melamine formaldehyde resins, benzoguanamineformaldehyde resins, urea formaldehyde resins and glycolurilformaldehyde resins. Polyisocyanates are resins with two or moreisocyanate groups, including both monomeric aliphatic diisocyanates,monomeric aromatic diisocyanates and their polymers. Typical aliphaticdiisocyanates include hexamethylene diisocyanate, isophoronediisocyanate and hydrogenated diphenylmethane diisocyanate. Typicalaromatic isocyanates include toluene diisocyanates and diphenylmethanediisocyanates.

If desired, the compositions of the present invention may contain otheringredients, for example resins (where these do not already constitutethe organic medium), binders, co-solvents, cross-linking agents,fluidising agents, wetting agents, anti-sedimentation agents,plasticisers, surfactants, dispersants other than the compound of thepresent invention, humectants, anti-foamers, anti-cratering agents,rheology modifiers, heat stabilizers, light stabilizers, UV absorbers,antioxidants, leveling agents, gloss modifiers, biocides andpreservatives.

The compositions typically contain from 1 to 95% by weight of theparticulate solid, the precise quantity depending on the nature of thesolid and the quantity depending on the nature of the solid and therelative densities of the solid and the polar organic liquid. Forexample, a composition in which the solid is an organic material, suchas an organic pigment, in one embodiment contains from 15 to 60% byweight of the solid whereas a composition in which the solid is aninorganic material, such as an inorganic pigment, filler or extender, inone embodiment contains from 40 to 90% by weight of the solid based onthe total weight of composition.

The compositions containing an organic liquid may be prepared by any ofthe conventional methods known for preparing dispersions. Thus, thesolid, the organic medium and the dispersant may be mixed in any order,the mixture then being subjected to a mechanical treatment to reduce theparticles of the solid to an appropriate size, for example by high speedmixing, ball milling, basket milling, bead milling, gravel milling, sandgrinding, attrition grinding, two roll or three roll milling, plasticmilling until the dispersion is formed. Alternatively, the solid may betreated to reduce its particle size independently or in admixture witheither the organic medium or the dispersant, the other ingredient oringredients then being added and the mixture being agitated to providethe composition. The composition can also be made by grinding or millingthe dry solid with the dispersant and then adding the liquid medium ormixing the solid with the dispersant in a liquid medium in a pigmentflushing process.

The composition of the present invention is particularly suited toliquid dispersions. In one embodiment, such dispersion compositionscomprise:

-   -   a) from 0.5 to 80 parts of a particulate solid;    -   b) from 0.1 to 79.6 parts of a polymer/dispersant of Formula 1;        and    -   c) from 19.9 to 99.4 parts of an organic liquid.        wherein all relative parts are by weight and the amounts        (a)+(b)+(c)=100.

In one embodiment, component a) comprises from 0.5 to 30 parts of apigment and such dispersions are useful as (liquid) inks, paints andmillbases.

If a composition is required comprising a particulate solid and adispersant of Formula 1 in dry form, the organic liquid is typicallyvolatile so that it may be readily removed from the particulate solid bya simple separation means such as evaporation. In one embodiment, thecomposition comprises the organic liquid.

If the dry composition consists essentially of the dispersant of formula(1) and the particulate solid, it typically contains at least 0.2%, atleast 0.5% or at least 1.0% dispersant of Formula 1 based on weight ofthe particulate solid. In one embodiment, the dry composition containsnot greater than 100%, not greater than 50%, not greater than 20% or notgreater than 10% by weight of dispersant of Formula 1 based on theweight of the particulate solid.

As disclosed herein, the compositions of the invention are suitable forpreparing millbases wherein the particulate solid is milled in anorganic liquid in the presence of a compound for Formula 1.

Thus, according to a still further aspect of the invention, there isprovided a millbase comprising a particulate solid, an organic liquidand a polymer of formula (1).

Typically, the millbase contains from 20 to 70% by weight particulatesolid based on the total weight of the millbase. In one embodiment, theparticulate solid is not less than 10 or not less than 20% by weight ofthe millbase. Such millbases may optionally contain a binder addedeither before or after milling.

In one embodiment, the binder is a polymeric material capable of bindingthe composition on volatilisation of the organic liquid.

Binders are polymeric materials including natural and syntheticmaterials. In one embodiment, binders include poly(meth)acrylates,polystyrenics, polyesters, polyurethanes, alkyds, polysaccharides suchas cellulose, nitrocellulose, and natural proteins such as casein. Thebinder may be nitrocellulose. In one embodiment, the binder is presentin the composition at more than 100% based on the amount of particulatesolid, more than 200%, more than 300% or more than 400%.

The amount of optional binder in the millbase can vary over wide limitsbut is typically not less than 10%, and often not less than 20% byweight of the continuous/liquid phase of the millbase. In oneembodiment, the amount of binder is not greater than 50% or not greaterthan 40% by weight of the continuous/liquid phase of the millbase.

The amount of dispersant in the millbase is dependent on the amount ofparticulate solid but is typically from 0.5 to 5% by weight of themillbase.

Dispersions and millbases made from the composition of the invention areparticularly suitable for use in non-aqueous and solvent freeformulations in which energy curable systems (ultra-violet, laser light,infra-red, cationic, electron beam, microwave) are employed withmonomers, oligomers, etc. or a combination present in the formulation.They are particularly suitable for use in coatings such as paints,varnishes, inks, other coating materials and plastics. Suitable examplesinclude their use in low, medium and high solids paints, generalindustrial paints including baking, two component and metal coatingpaints such as coil and can coatings, powder coatings, UV-curablecoatings, wood varnishes; inks, such as flexographic, gravure, offset,lithographic, letterpress or relief, screen printing and printing inksfor packaging printing, non-impact inks such as inkjet inks includingcontinuous inkjet and drop on demand inkjet which include thermal, piezoand electrostatic, phase change inks and hot melt wax inks, inks forink-jet printers and print varnishes such as overprint varnishes; polyoland plastisol dispersions; non-aqueous ceramic processes, especiallytape-casting, gel-casting, doctor-blade, extrusion and injectionmoulding type processes, a further example would be in the preparationof dry ceramic powders for isostatic pressing; composites such as sheetmoulding and bulk moulding compounds, resin transfer moulding,pultrusion, hand-lay-up and spray-lay-up processes, matched diemoulding; construction materials like casting resins, cosmetics,personal care like nail coatings, sunscreens, adhesives, toners such asliquid toners, plastics materials and electronic materials such ascoating formulations for color filter systems in displays includingorganic light-emitting diode (OLED) devices, liquid crystal displays andelectrophoretic displays, glass coatings including optical fibercoatings, reflective coatings or anti-reflective coatings, conductiveand magnetic inks and coatings. They are useful in the surfacemodification of pigments and fillers to improve the dispersibility ofdry powders used in the above applications. Further examples of coatingmaterials are given in Bodo Muller, Ulrich Poth, Lackformulierung undLackrezeptur, Lehrbuch fr Ausbildung und Praxis, Vincentz Verlag,Hanover (2003) and in P. G. Garrat, Strahlenhartung, Vincentz Verlag,Hanover (1996). Examples of printing ink formulations are given in E. W.Flick, Printing Ink and Overprint Varnish Formulations—RecentDevelopments, Noyes Publications, Park Ridge N.J., (1990) and subsequenteditions.

In one embodiment, the composition of the invention further includes oneor more additional known dispersants.

The following examples provide illustrations of the invention. Theseexamples are non exhaustive and are not intended to limit the scope ofthe invention.

EXAMPLES

Reagents

Lauric acid from Sigma Aldrich

ε-Caprolactone from Sigma Aldrich

δ-Valerolactone from Sigma Aldrich

(L+D)-Lactide from Sigma Aldrich

L-Lactide from Sigma Aldrich

Ricinoleic acid from Jayant Agro Organics Limited India

Zirconium (IV) butoxide solution from Sigma Aldrich, 80 wt. % in1-butanol Acetic anhydride from Sigma Aldrich

Epomin SP018 polyethyleneimine from Nippon Shokubai, MW 1800

3-Dimethylaminopropylamine from Sigma Aldrich

Dimethyl sulphate from Sigma Aldrich

U.S. Pat. No. 6,197,877 Example 198—this is made in accordance to theexample 198 from U.S. Pat. No. 6,197,877, with the exception that aminediethanolamine is not added and hence the material is present in itsacid form.

Orthophosphoric acid from Sigma Aldrich

3-Isopropenyl-α,α-dimethylbenzylisocyanate from Sigma Aldrich

2-Butanone from Fisher Scientific

Acetic anhydride from Fisher Scientific

Propionic anhydride from Sigma Aldrich

Dowanol MPA from Sigma Aldrich

Phthalic anhydride from Sigma Aldrich

Dimethyl sulphate from Sigma Aldrich

Ethyl acrylate from Sigma Aldrich

Epomin SP012 polyethyleneimine from Nippon Shokubai, MW 1200

Epomin SP006 polyethyleneimine from Nippon Shokubai, MW 600

Triethylenetetramine from Sigma Aldrich

2,2-Bis(hydroxymethyl)butyric acid from sigma Aldrich

Step 1—Polyester 1

Charged lauric acid (696.64 parts), ε-caprolactone (3562.51 parts bywt.), and lactide (1747.09 parts) to reaction vessel and heated to 100°C. under nitrogen. When at temperature, charged zirconium butoxidesolution (41.80 parts) and increased the temperature to 180° C. Afterseven hours, reaction stopped to yield a viscous liquid/paste, with anacid value of 34.05 mgKOH/g, this is a carboxylic acid terminatedpolyester called Polyester 1.

Step 1—Polyester 2

Charged lauric acid (117.38 parts), ε-caprolactone (281.24 parts bywt.), valerolactone (246.72 parts) and lactide (352.82 parts) toreaction vessel and heated to 100° C. under nitrogen. When attemperature, charged zirconium butoxide solution (7.01 parts) andincreased the temperature to 180° C. After seven hours, reaction stoppedto yield a viscous liquid/paste, with an acid value of 36.97 mgKOH/g,this is a carboxylic acid terminated polyester called Polyester 2.

Step 1—Polyester 3

Charged lauric acid (30.66 parts), ε-caprolactone (314.28 parts by wt.),and lactide (154.27 parts) to reaction vessel and heated to 100° C.under nitrogen. When at temperature, charged zirconium butoxide solution(3.50 parts) and increased the temperature to 180° C. After seven hours,reaction stopped to yield a viscous liquid/paste, with an acid value of23.36 mgKOH/g, this is a carboxylic acid terminated polyester calledPolyester 3.

Step 1—Polyester 4

Charged lauric acid (130.24 parts), ε-caprolactone (247.88 parts bywt.), and lactide (121.72 parts) to reaction vessel and heated to 100°C. under nitrogen. When at temperature, charged zirconium butoxidesolution (3.50 parts) and increased the temperature to 180° C. Afterseven hours, reaction stopped to yield a viscous liquid/paste, with anacid value of 76.32 mgKOH/g, this is a carboxylic acid terminatedpolyester called Polyester 4.

Step 1—Polyester 5

Charged ricinoleic acid (252.28 parts) to reaction vessel and heated to100° C. under nitrogen. When at temperature, charged zirconium butoxidesolution (0.76 parts) and increased the temperature to 195° C. Afterfourteen hours, reaction stopped to yield a viscous liquid/paste, withan acid value of 33.64 mgKOH/g, this is a carboxylic acid terminatedpolyester called Polyester 5.

Step 1—Polyester 6

Charged lauric acid (34.72 parts), ε-caprolactone (178.1 parts by wt.),and L-lactide (87.3 parts) to reaction vessel and heated to 100° C.under nitrogen. When at temperature, charged zirconium butoxide solution(2.10 parts) and increased the temperature to 180° C. After seven hours,reaction stopped to yield a viscous liquid/paste, with an acid value of30.21 mgKOH/g, this is a carboxylic acid terminated polyester calledPolyester 6.

Step 1—Polyester 7

Charged lauric acid (30.49 parts), ε-caprolactone (171.1 parts by wt.),and L-lactide (57.03 parts) to reaction vessel and heated to 100° C.under nitrogen. When at temperature, charged zirconium butoxide solution(0.78 parts) and increased the temperature to 180° C. After 18 hours,reaction stopped to yield a viscous liquid/paste, with an acid value of37.49 mgKOH/g, this is a carboxylic acid terminated polyester calledPolyester 7.

Step 1—Polyester 8

2,2-Bis(hydroxymethyl)butyric acid (7.76 parts), ε-caprolactone (35.85parts), δ-valerolactone (31.45 parts) and lauric acid (10.49 parts) werecharged to a reaction vessel and heated to 120° C. under nitrogen, afterone hour charged zirconium butoxide solution (0.26 parts) and increasedthe temperature to 180° C. After 20 hours reaction stopped to yieldyellow liquid, this is branched polyester 8.

Step 2—Polyester Anhydride 1

Charged Polyester 1 (250.02 parts) and acetic anhydride (19.05 parts) toa reaction vessel and heated to 120° C. under nitrogen with a dean andstark trap fitted to the reaction vessel. After a further six hours,increased the temperature to 150° C. After a further 17 hours, removedthe dean and stark trap to leave an open port. After a further one hour,reaction stopped and poured off to yield a viscous liquid/paste, this isan anhydride terminated version of the above polyester and is calledPolyester anhydride 1.

Step 2—Polyester Anhydride 2

Charged Polyester 2 (250.09 parts) and acetic anhydride (20.15 parts) toa reaction vessel and heated to 120° C. under nitrogen with a dean andstark trap fitted to the reaction vessel. After a further six hours,increased the temperature to 150° C. After a further 17 hours, removedthe dean and stark trap to leave an open port. After a further one hour,reaction stopped and poured off to yield a viscous liquid/paste, this isan anhydride terminated version of the above polyester and is calledPolyester anhydride 2.

Step 2—Polyester Anhydride 3

Charged Polyester 3 (85.75 parts) and acetic anhydride (4.29 parts) to areaction vessel and heated to 120° C. under nitrogen with a dean andstark trap fitted to the reaction vessel. After a further six hours,increased the temperature to 150° C. After a further 17 hours, removedthe dean and stark trap to leave an open port. After a further one hour,reaction stopped and poured off to yield a viscous liquid/paste, this isan anhydride terminated version of the above polyester and is calledPolyester anhydride 3.

Step 2—Polyester Anhydride 4

Charged Polyester 4 (101.32 parts) and acetic anhydride (16.91 parts) toa reaction vessel and heated to 120° C. under nitrogen with a dean andstark trap fitted to the reaction vessel. After a further six hours,increased the temperature to 150° C. After a further 17 hours, removedthe dean and stark trap to leave an open port. After a further one hour,reaction stopped and poured off to yield a viscous liquid/paste, this isan anhydride terminated version of the above polyester and is calledPolyester anhydride 4.

Step 2—Polyester Anhydride 5

Charged Polyester 5 (144.5 parts) and acetic anhydride (19.46 parts) toa reaction vessel and heated to 120° C. under nitrogen with a dean andstark trap fitted to the reaction vessel. After a further six hours,increased the temperature to 150° C. After a further 17 hours, removedthe dean and stark trap to leave an open port. After a further one hour,reaction stopped and poured off to yield a viscous liquid/paste, this isan anhydride terminated version of the above polyester and is calledPolyester anhydride 5.

Step 2—Polyester Anhydride 6

Charged Polyester 1 (109.68 parts) and propionic anhydride (10.69 parts)to a reaction vessel and heated to 140° C. under nitrogen with a deanand stark trap fitted to the reaction vessel. After a further six hours,increased the temperature to 170° C. After a further 17 hours, removedthe dean and stark trap to leave an open port. After a further one hour,reaction stopped and poured off to yield a viscous liquid/paste, this isan anhydride terminated version of the above polyester and is calledPolyester anhydride 6.

Step 2—Polyester Anhydride 7

Charged Polyester 6 (144.16 parts) and acetic anhydride (9.50 parts) toa reaction vessel and heated to 120° C. under nitrogen with a dean andstark trap fitted to the reaction vessel. After a further six hours,increased the temperature to 150° C. After a further 17 hours, removedthe dean and stark trap to leave an open port. After a further one hour,reaction stopped and poured off to yield a viscous liquid/paste, this isan anhydride terminated version of the above polyester and is calledPolyester anhydride 7.

Step 2—Polyester Anhydride 8

Charged Polyester 7 (209.17 parts) and acetic anhydride (15.81 parts) toa reaction vessel and heated to 120° C. under nitrogen with a dean andstark trap fitted to the reaction vessel. After a further six hours,increased the temperature to 150° C. After a further 17 hours, removedthe dean and stark trap to leave an open port. After a further one hour,reaction stopped and poured off to yield a viscous liquid/paste, this isan anhydride terminated version of the above polyester and is calledPolyester anhydride 8.

Step 2—Polyester Anhydride 9

Branched polyester 8 (60.86 parts) and acetic anhydride (7.36 parts)were charged to a reaction vessel under nitrogen and heated to 120° C.,after 4 hours the temperature was increased to 150° C. and the reactionstirred for a further 26 hours, to yield a yellow liquid, branchedpolyester anhydride 9.

Step 3—Dispersant 1

Charged Polyester anhydride 1 (49.34 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP018 (3.80 parts,which had been pre heated to 70° C.). After one hour, stopped thereaction to yield a viscous liquid/paste, with an acid value of 25.2mgKOH/g and a base equivalence of 1489.15 this is Dispersant 1.

Step 3—Dispersant 2

Charged Polyester anhydride 1 (37.50 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP018 (12.50 partswhich had been pre heated to 70° C.). After one hour, stopped thereaction to yield a viscous liquid/paste, with an acid value of 26.71mgKOH/g and a base equivalence of 413.96 this is Dispersant 2.

Step 3—Dispersant 3

Charged Polyester anhydride 1 (30.72 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP018 (1.50 partswhich had been pre heated to 70° C.). After one hour, stopped thereaction to yield a viscous liquid/paste, with an acid value of 26.18mgKOH/g and a base equivalence of 2220.07 this is Dispersant 3.

Step 3—Dispersant 4

Charged Polyester anhydride 2 (25.07 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP018 (1.50 partswhich had been pre heated to 70° C.) and 2-butanone (53.58 parts). Afterone hour, stopped the reaction to yield a low viscous liquid, with anacid value of 9.51 mgKOH/g and a base equivalence of 4412.13 this isDispersant 4.

Step 3—Dispersant 5

Charged Polyester anhydride 3 (35.57 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP018 (2.74 partswhich had been pre heated to 70° C.). After one hour, stopped thereaction to yield a viscous liquid/paste, with an acid value of 46.32mgKOH/g and a base equivalence of 1390.45 this is Dispersant 5.

Step 3—Dispersant 6

Charged Polyester anhydride 4 (51.39 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP018 (3.95 partswhich had been pre heated to 70° C.). After one hour, stopped thereaction to yield a viscous liquid/paste, with an acid value of 21.52mgKOH/g and a base equivalence of 1835.20 this is Dispersant 6.

Step 3—Dispersant 7

Charged Polyester anhydride 6 (45.82 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP018 (3.53 parts),which had been pre heated to 70° C. After one hour, stopped the reactionto yield a viscous liquid/paste, with an acid value of 21.57 mgKOH/g anda base equivalence of 1498.59 this is Dispersant 7.

Step 3—Dispersant 8

Charged Polyester anhydride 7 (45.68 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP018 (3.52 parts),which had been pre heated to 70° C. After one hour, stopped the reactionto yield a viscous liquid/paste, with an acid value of 22.99 mgKOH/g anda base equivalence of 4609.27 this is Dispersant 8.

Step 3—Dispersant 9

Charged Dispersant 1 (97.49 parts) to a reaction vessel and heated to70° C. under nitrogen, then charged phthalic anhydride (1.95 parts) andDowanol MPA (99.90 parts), which had been pre heated to 70° C. After onehour, stopped the reaction to yield a viscous liquid/paste, with an acidvalue of 17.73 mgKOH/g and a base equivalence of 3772.14 this isDispersant 9.

Step 3—Dispersant 10

Charged Dispersant 1 (101.78 parts) to a reaction vessel and heated to70° C. under nitrogen, then charged dimethylsulphate (2.10 parts) whichhad been pre heated to 70° C. Dowanol MPA (103.1 parts). After one hour,stopped the reaction to yield a viscous liquid/paste, with an acid valueof 15.48 mgKOH/g and a base equivalence of 4609.27 this is Dispersant10.

Step 3—Dispersant 11

Charged Dispersant 1 (98.72 parts) to a reaction vessel and heated to70° C. under nitrogen, then charged ethyl acrylate (1.97 parts), whichhad been pre heated to 70° C. After one hour, stopped the reaction toyield a viscous liquid/paste, with an acid value of 25.39 mgKOH/g and abase equivalence of 1803.49 this is Dispersant 11.

Step 3—Dispersant 12

Charged Dispersant 1 (98.03 parts) to a reaction vessel and heated to70° C. under nitrogen, then charged caprolactone (1.97 parts), which hadbeen pre heated to 70° C. and Dowanol MPA (99.92 parts). After one hour,stopped the reaction to yield a viscous liquid/paste, with an acid valueof 13.95 mgKOH/g and a base equivalence of 3647.37 this is Dispersant12.

Step 3—Dispersant 13

Charged Dispersant 1 (92.54 parts) to a reaction vessel and heated to70° C. under nitrogen, then charged U.S. Pat. No. 6,197,877 Example 198(1.95 parts), which had been pre heated to 70° C. After one hour,stopped the reaction to yield a viscous liquid/paste, with an acid valueof 27.87 mgKOH/g and a base equivalence of 1727.16 this is Dispersant13.

Step 3—Dispersant 14

Charged Dispersant 1 (78.72 parts) to a reaction vessel and heated to70° C. under nitrogen, then charged ortho phosphoric acid (85% w/w 1.55parts), which had been pre heated to 70° C. After one hour, stopped thereaction to yield a viscous liquid/paste, with an acid value of 30.25mgKOH/g and a base equivalence of 1818.48 this is Dispersant 14.

Step 3—Dispersant 15

Charged Polyester anhydride 5 (49.17 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP018 (3.78 parts),which had been pre heated to 70° C. After one hour, stopped the reactionto yield a viscous liquid/paste, with an acid value of 16.96 mgKOH/g anda base equivalence of 1181.82 this is Dispersant 15.

Step 3—Dispersant 16

Charged Dispersant 1 (102.2 parts) to a reaction vessel and heated to70° C. under nitrogen, then charged3-Isopropenyl-α,α-dimethylbenzylisocyanate (2.04 parts). After one hour,stopped the reaction to yield a viscous liquid/paste, with an acid valueof 23.39 mgKOH/g and a base equivalence of 1868.63 this is Dispersant16.

Step 3—Dispersant 17

Charged Polyester anhydride 2 (40.02 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP012 (3.10 parts),which had been pre heated to 70° C. After one hour, stopped the reactionto yield a viscous liquid/paste, with an acid value of 33.39 mgKOH/g anda base equivalence of 1388.84 this is Dispersant 17.

Step 3—Dispersant 18

Charged Polyester anhydride 8 (39.32 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Epomin SP006 (3.02 parts),which had been pre heated to 70° C. After one hour, stopped the reactionto yield a viscous liquid/paste, with an acid value of 28.19 mgKOH/g anda base equivalence of 1767.25 this is Dispersant 18.

Step 3—Dispersant 19

Charged Polyester anhydride 8 (33.00 parts) to a reaction vessel andheated to 70° C. under nitrogen, then charged Triethylenetetramine (2.54parts), which had been pre heated to 70° C. After one hour, stopped thereaction to yield a viscous liquid/paste, with an acid value of 22.28mgKOH/g and a base equivalence of 1664.46 this is Dispersant 19.

Step 3—Dispersant 20

Branched polyester anhydride 9 (40.84 parts) was charged to a reactionvessel and heated to 70° C. under nitrogen, when at temperature, chargedEpomin SP-006 (3.14 parts, this had been pre-heated to 70° C.) andstirred for one hour. After this time, product poured of to yield aviscous yellow liquid, with an acid value of 27.75 mgKOH/g and an abaseequivalence of 2307.36, this is Branched dispersant 20.

COMPARATIVE EXAMPLES Comparative Example 1

Based off method for example 30 in U.S. Pat. No. 6,197,877. ChargedPolyester 1 (77.47 parts) to reaction and heated to 70° C., then chargedEpomin SP018 (5.95 parts, which had been pre-heated to 70° C.), andincreased the temperature to 120° C. After six hours, reaction stoppedto yield a viscous liquid/paste, with an acid value of 42.2 mgKOH/g anda base equivalence of 2013.9 this is Comparative example 1.

Comparative Example 2

Charged Polyester 5 (15.28 parts) to reaction and heated to 70° C., thencharged Epomin SP018 (1.18 parts, which had been pre-heated to 70° C.),and increased the temperature to 120° C. After six hours, reactionstopped to yield a viscous liquid/paste, with an acid value of 20.00mgKOH/g and a base equivalence of 1338.14 this is Comparative example 2.

APPLICATION TESTING

Application Testing Reagents

Dowanol MPA—from sigma Aldrich

Regal Black 400R—from Cabot

3 mm Glass beads—from Sigmund Lindner

Toluene—from Fisher Scientific

Photomer 4226—diproyleneglycol diacrylate from IGM resins

Photomer 5429—Polyester tetraacrylate from IGM resins

Solsperse 22000—yellow synergist from Lubrizol Ltd

Irgalite Yellow D1115—Pigment yellow 13 from BASF

Ebecryl EB 160—a triacrylate monomer from Allnex

Ebecryl EB 657—an Oligomer from Allnex

Photo initiator blend—is a mixture of Speedcure EDB (5 parts), SpeedcureITX (3 parts), Ebecryl EB 160 (8 parts), Ebecryl EB 40 (0.5 parts) andDow Corning 57 (0.5 parts).

Speedcure EDB—from Lambson

Speedcure ITX—from Lambson

Ebecryl EB 40—from Allnex

Dow Corning 57—is an ink additive from Dow Corning

Application Results

Each Dispersant (0.6 parts) indicated in Table 1 below was added to an 8dram vial and Dowanol MPA (6.40 parts) was added. The dispersant wasthen dissolved by shaking and heating as necessary. When the dispersantwas dissolved, 3 mm glass beads (17 parts) were added, followed by RegalBlack 400R (3 parts). The vials were then sealed and shaken on ahorizontal shaker for 16 hours. The resulting dispersion was thenassessed for fluidity using an arbitrary scale of A to E (good to bad).

TABLE 1 Pigment Dispersion Results Example Fluidity Grade ComparativeExample 1 E Dispersant 1 A Dispersant 2 A Dispersant 3 C Dispersant 4* ADispersant 5 A Dispersant 6 B Dispersant 7 A Dispersant 8 A Dispersant9* A Dispersant 10* A Dispersant 11 A Dispersant 12* A Dispersant 13 ADispersant 14 A Dispersant 16 A Dispersant 17 B Dispersant 18 ADispersant 19 B Note all dispersants marked with a * are 50% active andhence twice as much dispersant is used (1.2 parts rather than 0.6 parts)and the extra weight is removed from the solvent used (5.80 parts ratherthan 6.40 parts).

Each Dispersant (0.6 parts) indicated in Table 2 below was added to an 8dram vial and Toluene (6.40 parts) was added. The dispersant was thendissolved by shaking and heating as necessary. When the dispersant wasdissolved, 3 mm glass beads (17 parts) were added, followed by RegalBlack 400R (3 parts). The vials were then sealed and shaken on ahorizontal shaker for 16 hours. The resulting dispersion was thenassessed for fluidity using an arbitrary scale of A to E (good to bad).

TABLE 2 Pigment Dispersion Results Example Fluidity Grade ComparativeExample 2 A Dispersant 15 A

Each Dispersant (2.88 parts) indicated in Table 3 below was added to an8 ounce jar and with Photomer 4226 (46.66 parts) and Photomer 5429(15.56 parts). The dispersant was then dissolved by shaking and heatingas necessary. When the dispersant was dissolved, Solsperse 22000 (0.50parts) was added along with Irgalite Yellow D1115 (14.40 parts) and 3 mmglass beads (250 parts) were added. The jars were then sealed and shakenon a scandex shaker for 4 hours, to give a mill base.

11.08 parts of each mill base was then taken and mixed with Ebecryl EB160 (4.72 parts), Ebecryl EB 657 (0.80 parts) and Photo initiator blend(3.40 parts) in a vial, to yield an Ink. These inks were then stored ina 50° C. oven for 1 week, then removed from the oven and their viscositymeasured on a TA instruments Discovery Hybrid HR-1 rheometer at shearrate 100/s.

TABLE 3 Ink Storage Viscosity Example Viscosity measurement Pa · sComparative Example 1 Gel* Dispersant 1 0.32 *This sample had become asolid gel in the vial and impossible to measure.Gardener Colour Testing

The colour of the dispersants were measured against the Gardener ColourScale using a Lovibond Comparator 2000+ and the results are recordedbelow in Table 4.

TABLE 4 Gardener Colour Results Example Gardiner Colour ComparativeExample 1 >18 Dispersant 1 13 Dispersant 2 12 Dispersant 3 15 Dispersant4 10 Dispersant 5 >18 Dispersant 6 >18 Dispersant 7 14 Dispersant 8 7Dispersant 9 14 Dispersant 10 14 Dispersant 11 14 Dispersant 12 14Dispersant 13 14 Dispersant 14 14 Dispersant 16 14 Dispersant 17 13Dispersant 18 13 Dispersant 19 13 Comparative Example 2 17 Dispersant 1512Application Results Dispersant 20

Dispersant 20 (0.25 parts by wt.) was added to a vial and Dowanol MPA(8.25 parts) was added. The dispersant was then dissolved by shaking andheating as necessary. When the dispersant was dissolved, 3 mm glassbeads (17 parts) were added, followed by Heligen Blue L7101F (1.5parts). The vial was then sealed and shaken on a horizontal shaker for16 hours. The resulting dispersion was then assessed for fluidity andwas graded an A.

As used herein, the transitional term “comprising”, which is synonymouswith “including”, “containing,” or “characterized by”, is inclusive oropen-ended and does not exclude additional, un-recited elements ormethod steps. However, in each recitation of “comprising” herein, it isintended that the term also encompass, as alternative embodiments, thephrases “consisting essentially of” and “consisting of”, where“consisting of” excludes any element or step not specified and“consisting essentially of” permits the inclusion of additionalun-recited elements or steps that do not materially affect the basic andnovel characteristics of the composition or method under consideration.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

What is claimed is:
 1. A dispersant of the following structure:

wherein: MA is a multi-amine species; PE1 is a polyester chain of numberaverage molecular weight between 500 and 4,000 g/mole attached to themulti amine species (MA) via an amide bond; wherein a carbonyl group isformed from a terminal group of PE1 and a nitrogen from the MA; PE2 is apolyester chain of number average molecular weight between 500 and 4,000g/mole attached to the multi amine species (MA) via a salt linkage;wherein a deprotonated carboxylic acid group is formed from a terminalgroup of PE2 and a protonated nitrogen from the MA; A1 is the residue ofa C₂₋₅ carboxylic acid attached to the MA via an amide bond, wherein acarbonyl group is formed from a terminal group of A1 and a nitrogen fromthe MA; A2 is the residue of a C₂₋₅ carboxylic acid attached to the MAvia a salt linkage, wherein a deprotonated carboxylic acid group isformed from a terminal group of A2 and a protonated nitrogen from theMA; the relative molar ratios of amide bonds represented by p and p′ tosalt linkages represented by q and q′ are between 5:95 and 50:50; p+p′can never be greater than q+q′; p is 1 or greater than 1, and p′ is 1 orgreater than 1; q is 1 or greater than 1, and q′ is 1 or greater than 1;and p+p′+q+q′ is between 4 and
 2000. 2. The dispersant composition ofclaim 1, wherein MA is selected from the group consisting of anon-polymeric alkyl amine with 3 or more nitrogen atoms, polyvinylamine,or polyallylamine.
 3. The dispersant composition of claim 1, wherein MAcomprises polyethyleneimine or modified polyethyleneimine.
 4. Thedispersant of claim 1, wherein p+q is on average from 4 to
 36. 5. Thedispersant composition of claim 1, wherein said PE1 is of the formulaR₁—[OR₃—C(═O)]_(n)— and said PE2 is of the formula R₁—[OR₃—C(═O)]_(n)—O⁻wherein: R₁ is H— or R₂C(═O)—; R₂ is a branched or linear, saturated orunsaturated hydrocarbon chain containing between 1 and 25 carbons atoms;R₃ is a branched or linear, saturated or unsaturated hydrocarbon chaincontaining between 1 and 25 carbons atoms or —R₄—OC(═O)R₅—; R₄ is abranched or linear, saturated or unsaturated hydrocarbon chaincontaining between 2 and 30 carbons atoms; R₅ is a branched or linear,saturated or unsaturated hydrocarbon chain containing between 1 and 20carbons atoms; and n is between 3 and
 43. 6. The dispersant compositionof claim 5, wherein at least 10 mole % of the R₃ units are linear orbranched alkyl groups of 1 to 5 carbon atoms.
 7. The dispersantcomposition of claim 5, wherein at least 5 mole % of the R₃ units arelinear or branched alkyl groups of 4 and/or 5 carbon atoms.
 8. Thedispersant composition of claim 5, wherein at least 10 mole % of the R₃units are linear or branched alkyl groups of 6 to 17 carbon atoms. 9.The dispersant composition of claim 5, wherein at least 5 mole % of theR₃ units are linear or branched alkyl groups of 1 or 2 carbon atoms. 10.The dispersant of claim 1, further comprising an amine group of saidmulti-amine species being a reaction product of: i) one more primary orsecondary amines groups of said multi-amine species with (a) anisocyanate, lactone, epoxy, anhydride, cyclic carbonate, (meth)acrylatevia Michael addition reaction, or a polymeric species having a groupthat reacts with a primary or secondary amine to form a salt or covalentbond; (b) an oxidizing species that could convert the amine group to anitric oxide; or (c) a salification agent; or ii) a tertiary amine groupreacted with a quaternization agent to form a quaternized amine group.11. A coating, paint, ink or plastic comprising the dispersant ofclaim
 1. 12. The dispersant composition of claim 1, wherein at least oneof PE1 or PE2 independently comprises from 1 to 50 mole % of at leastone di-hydroxy compound.
 13. The dispersant composition of claim 12,wherein the at least one di-hydroxy compound comprises at least one of2,2-bis(hydroxymethyl)butyric acid or 2,2-bis(hydroxymethyl)propionicacid.
 14. The dispersant composition of claim 5, wherein R₄ is abranched or linear, saturated or unsaturated hydrocarbon chaincontaining between 2 and 30 carbons atoms, which contains 1 or moreether linkages.